JP2001310946A - Method for production of polyphenylene ether resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing polyphenylene ether resin particles having a specified size suitable for drying, transporting and molding. SOLUTION: This method comprises the steps of obtaining a slurry solution of a polyphenylene ether resin after polymerization reaction, obtaining wet state polyphenylene ether resin by solid-liquid separation of the slurry solution, and pelletizing the wet state resin containing 0.5 to 0.9 g of a rich solvent per 1 g of dry polyphenylene ether resin agitated in warm water of 40 to 90 deg.C and in a condition satisfying the following formula: 25<=X.Y<=60 where X is the content (g) of the rich solvent in the wet state polyphenylene ether resin based on 1 g of dry polyphenylene ether resin and Y is the temperature of the warm water ( deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a granulation method in a method for producing polyphenylene ether. More specifically, the present invention relates to a method for granulating a wet polyphenylene ether resin after solid-liquid separation from a slurry solution of the polyphenylene ether resin after completion of the reaction.

[0002]

2. Description of the Related Art Polyphenylene ethers are generally obtained by oxidative polymerization of one or more phenol compounds using an aromatic hydrocarbon solvent in the presence of a complex catalyst containing copper, manganese or cobalt. . afterwards,
In order to remove the catalyst and by-products, which are impurities that adversely affect the physical properties of the polyphenylene ether, the reaction solution is washed by bringing it into contact with an aqueous solution of a polymerization terminator or an aqueous solution of a polymerization terminator and a reducing agent. Then, it solidifies in a non-solvent or a mixture of a non-solvent and a good solvent. In order to separate this solid content from the slurry solution, a method such as centrifugation or vacuum filtration is generally used, and a method for washing the polyphenylene ether after solid-liquid separation is to rinse or reslurry with a large amount of non-solvent. And solid-liquid separation.

In general, polyphenylene ether is prepared by using a mixed solvent of an aromatic hydrocarbon solvent and an alcohol in the presence of a complex catalyst containing copper, manganese, or cobalt in the presence of one or more phenol compounds. In the precipitation polymerization method in which polyphenylene ether resin particles are precipitated in the latter stage of the oxidative polymerization, a slurry solution is obtained. Thereafter, in order to remove the catalyst and by-products, which are impurities that adversely affect the physical properties of the polyphenylene ether, the reaction solution is washed by contacting with an aqueous solution of a polymerization terminator or an aqueous solution of a polymerization terminator and a reducing agent. Thereafter, methods such as centrifugation and vacuum filtration are generally used to separate the polyphenylene ether resin from the slurry solution, and the method of washing the polyphenylene ether after solid-liquid separation is to rinse or reslurry with a large amount of non-solvent. After that, solid-liquid separation is performed.

[0004] The polyphenylene ether resin obtained by any of the above-mentioned methods contains a large amount of fine particles. This is a cause of many troubles due to a problem that a drying device is limited in a particle drying process, a problem such as scattering in a transportation process, or a problem of poor biting of particles supplied from a hopper during molding. Has become.

Japanese Patent Publication No. 55-17775 discloses a method of enlarging the particle size of a polyphenylene ether resin powder by performing heat treatment in an aqueous dispersion of polyphenylene ether containing an organic solvent. At present, no effect has been obtained.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for reducing fine particles of wet polyphenylene ether resin obtained by solid-liquid separation after the reaction.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have obtained a wet state obtained by solid-liquid separation from a slurry solution of polyphenylene ether resin obtained after the polymerization reaction. When granulating the polyphenylene ether resin, a wet polyphenylene ether resin containing 0.5 to 0.9 g of a good solvent per 1 g of the dry polyphenylene ether resin is mixed in warm water at 40 to 90 ° C. and the following formula is satisfied. This is a method for producing a polyphenylene ether resin by stirring and granulating under the following conditions. 25 ≦ XY · 60 X: Content of good solvent in wet polyphenylene ether resin (g) (However, per 1 g of dry polyphenylene ether) Y: Temperature of hot water (° C)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyphenylene ether in the present invention is represented by a repeating unit of the general formula (1).

Embedded image (Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen,
An alkyl group, a substituted alkyl group, a halogen group, a phenyl group or a substituted phenyl group. )

Representative polyphenylene ethers are poly (2,6-dimethyl-1,4-phenylene) ether,
Poly (2-methyl-6-ethyl-1,4-phenylene)
Ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-)
1,4-phenylene) ether, poly (2,6-di-n)
-Propyl-1,4-phenylene) ether, poly (2
-Methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-)
Examples include homopolymers such as phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether, and poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether. Also, 2,6-
2,3,6- as a copolymer component in dimethylphenol
Examples include polyphenylene ether copolymers in which one or both of trimethylphenol and o-cresol are combined.

Further, the polyphenylene ether of the present invention contains, as a partial structure, various other phenylene ether units which have conventionally been proposed to be allowed to exist in the polyphenylene ether without departing from the gist of the present invention. You may go out. For example, Japanese Patent Application Laid-Open Nos. 1-297428 and 63-301222 disclose 2-
(Dialkylaminomethyl) -6-methylphenylene ether unit, 2- (N-alkyl-N-phenylaminomethyl) -6-methylphenylene ether unit, and a small amount of diphenoquinone or the like bonded in the main chain of polyphenylene ether resin What was done. further,
Polyphenylene ether modified with a compound having a carbon-carbon double structure (for example, JP-A-2-276823, JP-A-63-108059, JP-A-59-1984)
59724).

The molecular weight of the polyphenylene ether resin used in the present invention is 30.degree.
Preferably it is ~ 0.7. More preferably 0.2 to
A polyphenylene ether in the range of 0.6 remarkably exerts the effect of the present invention.

The polyphenylene ether of the present invention is disclosed, for example, in JP-B-42-3195 and JP-B-45-235.
As exemplified in JP-A-55-33, JP-A-64-33131 and the like, a phenol compound is oxidatively polymerized using a catalyst comprising a combination of a metal salt and various amines.
Examples of the polymerization solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, which are good solvents for polyphenylene ether, halogenated hydrocarbons such as dichloromethane, chloroform, and dichlorobenzene, and nitro compounds such as nitrobenzene. In addition, methanol,
Alcohols such as ethanol, aliphatic hydrocarbons such as hexane and heptane, and ketones such as acetone and methyl ethyl ketone can be mixed as long as polyphenylene ether does not precipitate during polymerization, and used as a polymerization solvent.

The concentration of the polyphenylene ether in the polyphenylene ether polymerization reaction solution in the present invention is in the range of 5 to 70%, preferably 10 to 50% by weight. In addition, the solution may contain a polymerization catalyst, a chemical for removing the catalyst, a chemical for removing by-products, and the like, in addition to the polyphenylene ether.

As a method of solidifying polyphenylene ether from the polyphenylene ether polymerization reaction solution, a method of adding a non-solvent for polyphenylene ether such as methanol to a solution to solidify polyphenylene ether particles is known. Also, a method using a mixture of water and alcohol as a non-solvent (Japanese Patent Publication No.
-23696). From the polyphenylene ether polymerization reaction solution in the present invention, solidification of the polyphenylene ether is a method of solidifying the polyphenylene ether reaction solution by continuously contacting the polyphenylene ether reaction solution with an alcohol or the like which is a non-solvent for the polyphenylene ether, or a non-solvent. Or a method of continuously contacting a mixture of water and water with a polyphenylene ether reaction solution to solidify the mixture. In this case, the weight ratio of non-solvent / good solvent is 0.5
It is preferable to set it to 3.0. Further, when supplying the polymerization reaction liquid, it is preferable to continuously solidify the polyphenylene ether in one or more stages of a stirring tank equipped with a reciprocating stirrer. Although the inside of the system is preferably carried out in an inert gas atmosphere, it is also possible to carry out the treatment in the presence of oxygen. Inert gases are generally nitrogen, argon,
Helium or the like is used. Generally, the residence time of polyphenylene ether in the solidification tank is required to be 1 to 120 minutes.

Further, the present invention is also applicable to a slurry solution containing a polyphenylene ether solid obtained by a production method of precipitating polyphenylene ether at a later stage of polymerization using a mixed solvent of a good solvent and a non-solvent of the above-mentioned polyphenylene ether. it can.

The average particle size of the wet polyphenylene ether resin suitable for applying the present invention is 25.
３００300 μm.

In the present invention, the solid-liquid separated wet polyphenylene ether resin contains 0.5 to 0.9 g, preferably 0.6 to 0.8 g of a good solvent per 1 g of dry polyphenylene ether resin. It is. The good solvent is the same as the above-mentioned solvent for the polymerization of the polyphenylene ether resin, and benzene, toluene and xylene are particularly preferable.

In the present invention, the solid-liquid separated wet polyphenylene ether resin contains 0.5 to 3.0 g of a non-solvent per 1 g of dry polyphenylene ether resin. The non-solvent is the same as the above-mentioned solidified solvent for the polyphenylene ether resin, and is particularly preferably methanol, ethanol, isopropanol, n-butanol and n-heptane.

In the present invention, the warm water to which the wet polyphenylene ether resin is added is 40 to 90.
° C, preferably 50-80 ° C. The amount of hot water used is 2 to 20 g per 1 g of polyphenylene ether resin in the polyphenylene ether resin in a wet state,
Preferably it is 4 to 10 g.

The stirring time between the wet polyphenylene ether resin and the hot water is usually 5 minutes to 5 hours, preferably 0.5 to 2 hours. Although the present invention can be carried out in a batch system, it is desirable to carry out the present invention industrially by a two-stage or more cascade method.

[0021]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 An apparatus in which two containers each having a 1.2 L stirrer, a slurry supply port, a cooler, an overflow port, and a heating jacket were connected in series was used. 40 kg /
At a speed of 30 ° C. and a wet polyphenylene ether resin slurry having a liquid content of 65% at 30 ° C. (1 g of dry resin)
(0.7 g of toluene) was supplied to the first stirring tank at a rate of 20 kg / hour by a slurry pump. The first-stage stirring tank was maintained at 60 ° C., and the second-stage stirring tank was maintained at 7 ° C.
It was kept at 0 ° C. After drying, the particle size distribution of the raw material and the particle size distribution of the product were measured. The results are shown in Table 1.

Table 1 Particle size Raw material (wt%) Product (wt%) 1700 μm or more 0.5 19.0 850 μm 3.9 46.4 250 μm 25.6 30.7 125 μm 5.6 3.3 106 μm 14.0 0.3 53 μm 23.3 0.3 38 μm 12.3 0.0 25 μm 12.4 0.0 25 μm or less 2.5 0.0

Example 2 The procedure of Example 1 was repeated except that the temperature of the first-stage stirring tank was 55 ° C., the temperature of the second-stage stirring tank was 75 ° C., and the raw material slurry was changed. The results are shown in Table 2.

Table 2 Particle size Raw material (wt%) Product (wt%) 1700 μm or more 0.2 22.4 850 μm 4.1 29.4 250 μm 27.4 34.1 125 μm 15.3 10.7 106 μm 15.3 1.3 53 μm 18.6 2.2 38 μm 8.2 0.0 25 μm 7.3 0.0 25 μm or less 3.2 0.0

Comparative Example 1 A wet polyphenylene ether resin slurry having a liquid content of 65% at 30 ° C. (containing 0.8 g of toluene with respect to 1 g of dry resin) was used. ° C
The procedure was performed in the same manner as in Example 1 except that the temperature of the second-stage stirring tank was changed to 80 ° C. However, large lumps were found in the first stage stirring tank.
After hours, it was generated and operation was not possible.

Comparative Example 2 Using a wet polyphenylene ether resin slurry having a liquid content of 65% at 30.degree. C. (containing 0.5 g of toluene with respect to 1 g of dry resin), using hot water at 40.degree. The temperature of the stirring tank in the second stage was set to 40 ° C.
The procedure was performed in the same manner as in Example 1 except for the following. The results are shown in Table 2.

Table 3 Particle Size Raw Material (wt%) Product (wt%) 1700 μm or more 0.1 0.6 850 μm 1.7 6.6 250 μm 22.7 37.7 125 μm 10.8 12.2 106 μm 9.0 5.7 53 μm 26.5 18.9 38 μm 10.8 8.3 25 μm 16.0 8.7 25 μm or less 2.4 1.2

[0029]

According to the method of the present invention, after the polymerization reaction of polyphenylene ether, the wet polyphenylene ether resin containing a large amount of fine particles separated into solid and liquid is subjected to a hot water treatment under a special vegetable condition, whereby the drying step is carried out. Thus, a polyphenylene ether resin having a particle size suitable for a molding step such as a transporting step and an extrusion molding can be obtained.

Claims (5)

[Claims] When a wet polyphenylene ether resin obtained by solid-liquid separation is granulated from a slurry solution of a polyphenylene ether resin obtained after a polymerization reaction, 0.1 g per 1 g of dry polyphenylene ether resin is obtained.
Polyphenylene ether resin in a wet state containing 5 to 0.9 g of a good solvent is granulated by stirring in warm water at 40 to 90 ° C. under conditions satisfying the following formula. Manufacturing method. 25 ≦ XY · 60 X: Content of good solvent in wet polyphenylene ether resin (g) (However, per 1 g of dry polyphenylene ether) Y: Temperature of hot water (° C) 2. The relationship between the content (X) g (per 1 g dry polyphenylene ether) of the good solvent of the wet polyphenylene ether resin and the temperature (Y) ° C. of the hot water satisfies the following expression. A method for producing a polyphenylene ether resin. 30 ≤ XY ≤ 50 3. The method for producing polyphenylene ether according to claim 1, wherein the good solvent for polyphenylene ether is at least one selected from the group consisting of benzene, toluene and xylene. 4. The method for producing polyphenylene ether according to claim 1, wherein the polyphenylene ether resin in a wet state contains 0.5 to 3.0 g of a non-solvent (per 1 g of dry polyphenylene ether). 5. The non-solvent of polyphenylene ether is at least one selected from the group consisting of methanol, ethanol, isopropanol, n-butanol and n-heptane.
The method for producing a polyphenylene ether according to claim 1, which is a seed.